Gender difference regarding schizandrin pharmacokinetics in rats

The difference in the pharmacokinetics of schizandrin (SZ) in male and female rats was studied. SZ concentrations in the plasma were determined after the intragastric (i.g) administration of 10 mg/kg and the intravenous (i.v) administration of 5 mg/kg in male and female rats, respectively. It was found that the plasma concentrations of SZ in female rats were significantly higher than those in male rats. Drug absolute bioavailability, based on the area under curve (AUC(0-tn)), in female rats was roughly 20 times of that in male rats. The terminate half-life (T(1/2)) in male rats was shorter than that in female rats. These results demonstrate the existence of marked gender differences for SZ in rats.